Rank is a system of categorizing the hierarchy of an armed force. See military rank for details on the history of the rank system.
Certain ranks, such as Fleet Admiral, General of the Army and General of the Air Force in the U.S., as well as Admiral of the Fleet, Field Marshal and Marshal of the RAF in the U.K., are usually assigned in war-time only.
In the British and Commonwealth Armies, a Brigadier is a Colonel in command of a brigade, who wears the insignia and title of such assignment. In the Royal and Commonwealth Navies, a Commodore is a Captain in command of a naval task group, flotilla or squadron, who wears the insignia and title of such assignment, and flies a broad pennant (as opposed to a flag) from his flagship.
In the Royal and Commonwealth Navies, a Midshipman is junior to an Army 2nd Lieutenant and an RAF Pilot Officer. This is because historically Midshipman was a training rank; nowadays however, officers only join as Midshipman if they are under 20 years of age. Because of the duration of training very few midshipmen reach their commissioning board before automatic promotion so the matter of what type of commission they are serving under is of little consequence.
Not listed are US warrant officers. In accordance with Army Regulation (AR) 135-100, Department of the Army Pamphlet (DA Pam) 600-11 and Army Field Manual (FM) 22-100 (para A-3), a warrant officer is an officer who can and does command, carry out military justice actions and sits both selection and promotion boards. A warrant officer is a single-track specialty officer, initially appointed by the Secretary of the Army, he/she receives a commission upon promotion to Chief Warrant Officer Two (CW2).
|Bundeswehr (Army)/Luftwaffe (Air Force)||Bundesmarine (Navy)|
|see 1||nominally supervises||US Army||USAF||USMC||USN||British Army||Royal Marines||Royal Navy||RAF|
|E-10||the senior enlisted person in each service||Sergeant Major of the Army||Chief Master Sergeant of the Air Force (CMSgtAF)||Sergeant Major of the Marine Corps||Master Chief Petty Officer of the Navy (MCPON)|
|E-9||Brigade (Army), Wing (USAF), Regiment (USN, USMC) or higher||Command Sergeant Major (CSM)||Command Chief Master Sergeant (CMSgt)||Sergeant Major (SgtMaj)||Command Master Chief Petty Officer (CMCPO)||Warrant Officer Class 1||Warrant Officer Class 1||Warrant Officer||Warrant Officer|
|E-9||Battalion (Army, USN, USMC), Group (USAF)||Sergeant Major (SGM)||Chief Master Sergeant (CMSgt)||Master Gunnery Sergeant (MGySgt)||Master Chief Petty Officer (MCPO)|
|E-8||Company (Army, USN, USMC), Squadron (USAF)||First Sergeant (1SG)||Senior Master Sergeant (SMSgt)||First Sergeant (1st Sgt)||Senior Chief Petty Officer (SCPO)||Warrant Officer Class 2||Warrant Officer Class 2|
|Master Sergeant (MSG)||Master Sergeant (MSgt)||Staff Sergeant||Colour Sergeant||Chief Petty Officer||Flight Sergeant|
|E-7||Platoon (Army, USN, USMC), Flight (USAF)||Sergeant First Class (SFC) or Platoon Sergeant||Master Sergeant (MSgt)||Gunnery Sergeant (GySgt)||Chief Petty Officer (CPO)||Sergeant||Sergeant||Petty Officer||Sergeant|
|E-6||Squad or Section||Staff Sergeant (SSG)||Technical Sergeant (TSgt)||Staff Sergeant (SSgt)||Petty Officer 1st Class (PO1)||Corporal||Corporal||Leading Rate||Corporal|
|E-5||Fireteam||Sergeant (SGT)||Staff Sergeant (SSgt)||Sergeant (Sgt)||Petty Officer 2nd Class (PO2)||Lance Corporal||Lance Corporal|
|E-4||Corporal (CPL) or Specialist Fourth Class (SP4)||Senior Airman (SRA)||Corporal (Cpl)||Petty Officer 3rd Class (PO3)||Private||Marine||Able Rate||Senior Aircraftman|
|E-3||Private First Class (PFC)||Airman First Class (A1C)||Lance Corporal (LCpl)||Seaman (SN)||Leading Aircraftman|
|E-2||Private (PV2)||Airman (Amn)||Private First Class (PFC)||Seaman Apprentice (SA)||Ordinary Rate||Aircraftman|
|E-1||Private (PV1)||Airman Basic (AB)||Private (Pvt)||Seaman Recruit (SR)|
1 Paygrade is used in the US military as to normalize the equivalent enlisted and officer ranks respectively. For example, the base pay of an E-8 is the same in the Air Force and the Army. In theory, those two E-8s will have equivalent levels of seniority and responsibility. When enlisted men from several services are together, the senior enlisted man is responsible for the group.